* into the buffer. In case of error ->start() and ->next() return
* ERR_PTR(error). In the end of sequence they return %NULL. ->show()
* returns 0 in case of success and negative number in case of error.
+ * Returning SEQ_SKIP means "discard this element and move on".
*/
-int seq_open(struct file *file, struct seq_operations *op)
+int seq_open(struct file *file, const struct seq_operations *op)
{
- struct seq_file *p = kmalloc(sizeof(*p), GFP_KERNEL);
- if (!p)
- return -ENOMEM;
+ struct seq_file *p = file->private_data;
+
+ if (!p) {
+ p = kmalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ file->private_data = p;
+ }
memset(p, 0, sizeof(*p));
- sema_init(&p->sem, 1);
+ mutex_init(&p->lock);
p->op = op;
- file->private_data = p;
/*
* Wrappers around seq_open(e.g. swaps_open) need to be
void *p;
int err = 0;
- down(&m->sem);
+ mutex_lock(&m->lock);
/*
* seq_file->op->..m_start/m_stop/m_next may do special actions
* or optimisations based on the file->f_version, so we want to
if (!p || IS_ERR(p))
break;
err = m->op->show(m, p);
- if (err)
+ if (err < 0)
break;
+ if (unlikely(err))
+ m->count = 0;
if (m->count < m->size)
goto Fill;
m->op->stop(m, p);
break;
}
err = m->op->show(m, p);
- if (err || m->count == m->size) {
+ if (m->count == m->size || err) {
m->count = offs;
- break;
+ if (likely(err <= 0))
+ break;
}
pos = next;
}
else
*ppos += copied;
file->f_version = m->version;
- up(&m->sem);
+ mutex_unlock(&m->lock);
return copied;
Enomem:
err = -ENOMEM;
static int traverse(struct seq_file *m, loff_t offset)
{
- loff_t pos = 0;
+ loff_t pos = 0, index;
int error = 0;
void *p;
m->version = 0;
- m->index = 0;
+ index = 0;
m->count = m->from = 0;
- if (!offset)
+ if (!offset) {
+ m->index = index;
return 0;
+ }
if (!m->buf) {
m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
if (!m->buf)
return -ENOMEM;
}
- p = m->op->start(m, &m->index);
+ p = m->op->start(m, &index);
while (p) {
error = PTR_ERR(p);
if (IS_ERR(p))
break;
error = m->op->show(m, p);
- if (error)
+ if (error < 0)
break;
+ if (unlikely(error)) {
+ error = 0;
+ m->count = 0;
+ }
if (m->count == m->size)
goto Eoverflow;
if (pos + m->count > offset) {
m->from = offset - pos;
m->count -= m->from;
+ m->index = index;
break;
}
pos += m->count;
m->count = 0;
if (pos == offset) {
- m->index++;
+ index++;
+ m->index = index;
break;
}
- p = m->op->next(m, p, &m->index);
+ p = m->op->next(m, p, &index);
}
m->op->stop(m, p);
return error;
loff_t seq_lseek(struct file *file, loff_t offset, int origin)
{
struct seq_file *m = (struct seq_file *)file->private_data;
- long long retval = -EINVAL;
+ loff_t retval = -EINVAL;
- down(&m->sem);
+ mutex_lock(&m->lock);
m->version = file->f_version;
switch (origin) {
case 1:
}
}
}
- up(&m->sem);
file->f_version = m->version;
+ mutex_unlock(&m->lock);
return retval;
}
EXPORT_SYMBOL(seq_lseek);
/**
* seq_release - free the structures associated with sequential file.
* @file: file in question
- * @inode: file->f_dentry->d_inode
+ * @inode: file->f_path.dentry->d_inode
*
* Frees the structures associated with sequential file; can be used
* as ->f_op->release() if you don't have private data to destroy.
}
EXPORT_SYMBOL(seq_printf);
-int seq_path(struct seq_file *m,
- struct vfsmount *mnt, struct dentry *dentry,
- char *esc)
+static char *mangle_path(char *s, char *p, char *esc)
+{
+ while (s <= p) {
+ char c = *p++;
+ if (!c) {
+ return s;
+ } else if (!strchr(esc, c)) {
+ *s++ = c;
+ } else if (s + 4 > p) {
+ break;
+ } else {
+ *s++ = '\\';
+ *s++ = '0' + ((c & 0300) >> 6);
+ *s++ = '0' + ((c & 070) >> 3);
+ *s++ = '0' + (c & 07);
+ }
+ }
+ return NULL;
+}
+
+/*
+ * return the absolute path of 'dentry' residing in mount 'mnt'.
+ */
+int seq_path(struct seq_file *m, struct path *path, char *esc)
{
if (m->count < m->size) {
char *s = m->buf + m->count;
- char *p = d_path(dentry, mnt, s, m->size - m->count);
+ char *p = d_path(path, s, m->size - m->count);
if (!IS_ERR(p)) {
- while (s <= p) {
- char c = *p++;
- if (!c) {
- p = m->buf + m->count;
- m->count = s - m->buf;
- return s - p;
- } else if (!strchr(esc, c)) {
- *s++ = c;
- } else if (s + 4 > p) {
- break;
- } else {
- *s++ = '\\';
- *s++ = '0' + ((c & 0300) >> 6);
- *s++ = '0' + ((c & 070) >> 3);
- *s++ = '0' + (c & 07);
- }
+ s = mangle_path(s, p, esc);
+ if (s) {
+ p = m->buf + m->count;
+ m->count = s - m->buf;
+ return s - p;
}
}
}
}
EXPORT_SYMBOL(seq_path);
+/*
+ * Same as seq_path, but relative to supplied root.
+ *
+ * root may be changed, see __d_path().
+ */
+int seq_path_root(struct seq_file *m, struct path *path, struct path *root,
+ char *esc)
+{
+ int err = -ENAMETOOLONG;
+ if (m->count < m->size) {
+ char *s = m->buf + m->count;
+ char *p;
+
+ spin_lock(&dcache_lock);
+ p = __d_path(path, root, s, m->size - m->count);
+ spin_unlock(&dcache_lock);
+ err = PTR_ERR(p);
+ if (!IS_ERR(p)) {
+ s = mangle_path(s, p, esc);
+ if (s) {
+ p = m->buf + m->count;
+ m->count = s - m->buf;
+ return 0;
+ }
+ }
+ }
+ m->count = m->size;
+ return err;
+}
+
+/*
+ * returns the path of the 'dentry' from the root of its filesystem.
+ */
+int seq_dentry(struct seq_file *m, struct dentry *dentry, char *esc)
+{
+ if (m->count < m->size) {
+ char *s = m->buf + m->count;
+ char *p = dentry_path(dentry, s, m->size - m->count);
+ if (!IS_ERR(p)) {
+ s = mangle_path(s, p, esc);
+ if (s) {
+ p = m->buf + m->count;
+ m->count = s - m->buf;
+ return s - p;
+ }
+ }
+ }
+ m->count = m->size;
+ return -1;
+}
+
+int seq_bitmap(struct seq_file *m, unsigned long *bits, unsigned int nr_bits)
+{
+ size_t len = bitmap_scnprintf_len(nr_bits);
+
+ if (m->count + len < m->size) {
+ bitmap_scnprintf(m->buf + m->count, m->size - m->count,
+ bits, nr_bits);
+ m->count += len;
+ return 0;
+ }
+ m->count = m->size;
+ return -1;
+}
+
static void *single_start(struct seq_file *p, loff_t *pos)
{
return NULL + (*pos == 0);
int single_release(struct inode *inode, struct file *file)
{
- struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
+ const struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
int res = seq_release(inode, file);
kfree(op);
return res;
}
EXPORT_SYMBOL(seq_release_private);
+void *__seq_open_private(struct file *f, const struct seq_operations *ops,
+ int psize)
+{
+ int rc;
+ void *private;
+ struct seq_file *seq;
+
+ private = kzalloc(psize, GFP_KERNEL);
+ if (private == NULL)
+ goto out;
+
+ rc = seq_open(f, ops);
+ if (rc < 0)
+ goto out_free;
+
+ seq = f->private_data;
+ seq->private = private;
+ return private;
+
+out_free:
+ kfree(private);
+out:
+ return NULL;
+}
+EXPORT_SYMBOL(__seq_open_private);
+
+int seq_open_private(struct file *filp, const struct seq_operations *ops,
+ int psize)
+{
+ return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM;
+}
+EXPORT_SYMBOL(seq_open_private);
+
int seq_putc(struct seq_file *m, char c)
{
if (m->count < m->size) {
return -1;
}
EXPORT_SYMBOL(seq_puts);
+
+struct list_head *seq_list_start(struct list_head *head, loff_t pos)
+{
+ struct list_head *lh;
+
+ list_for_each(lh, head)
+ if (pos-- == 0)
+ return lh;
+
+ return NULL;
+}
+
+EXPORT_SYMBOL(seq_list_start);
+
+struct list_head *seq_list_start_head(struct list_head *head, loff_t pos)
+{
+ if (!pos)
+ return head;
+
+ return seq_list_start(head, pos - 1);
+}
+
+EXPORT_SYMBOL(seq_list_start_head);
+
+struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos)
+{
+ struct list_head *lh;
+
+ lh = ((struct list_head *)v)->next;
+ ++*ppos;
+ return lh == head ? NULL : lh;
+}
+
+EXPORT_SYMBOL(seq_list_next);